1. Field of the Invention
The present invention relates to monitoring systems, specifically a cable theft monitoring system.
2. Description of the Related Art
Companies in the Asphalt, Concrete, Sand and Gravel, Crushing, Washing, Screening, Surface Mining, Underground Mining and other similar industries, have suffered greatly in the past due to theft of their power cables. These industries use copper cables to run motors and controls for their plants. The cables can vary in size from small enough to run a switch to large enough to power large horse-power motors. A single plant or operation may have thousands of feet of such cables and operation depends on every cable being in place and functioning properly.
Prices of these cables can vary from $0.75 per foot to over $50.00 per foot depending on the price of copper as a commodity and the diameter of the cable. These cables are often specialized and specifically approved for use in the industry and therefore expensive to replace. They are most often visible and accessible because they are suspended on utility poles or tied along equipment frames to lying on the ground.
The scrap price paid for copper in any market and any economy, makes this a highly sought after material, and leaves owners vulnerable to theft. Most often these thefts occur when plants and mines are shut down and idle during after hour non-working shifts, during weekends and holidays. Many projects use power that is generated on site so that when the generator is not functioning during non-work times there is no power in any of the cables. Therefore, the risk of electric shock when cutting the cable is virtually non-existent. If utility power is used the cables are almost always left with no power on during non-work times for cost and safety purposes. If for some reason power to any cable is left on during non-working times, then simply turning off a well labeled main disconnect or breaker will generally render an entire plant susceptible to easy wire theft.
The wire theft is often accomplished by cutting exposed wires with metal saws or cutters designed for normal cutting of wire during installation. The wire is often thrown into the back of trucks and driven from the crime scene to a location where it is stripped of all insulation. The wire is then taken to any metal recycler and is exchanged for a recycle price based on weight. Sometimes the thieves are employees of the operation.
Operations may have to be suspended for days or weeks as repairs and replacement cables are brought in and installed. Equipment and sensitive electronics may also be damaged depending on the method thieves use to remove the cabling. Therefore, companies are very motivated to protect their facilities and prevent cable theft.
Companies have installed security cameras to monitor plants during non-work periods. The cameras can record activity based on any movement within the field or view. The problems with this method are cameras are exposed to outside elements—wind, rain, snow, sleet, cold temperatures, high temperatures, and high humidity. These elements cause nuisance recordings, failures, dirty lenses, component damage. Recordings often only show that a theft did occur. No one is notified and often times a returning customer can only view how the theft was accomplished. The quality of the recording is not sufficient enough to get license numbers, identifying characteristics of people or even descriptions on vehicle. Banks use some of the best surveillance camera systems available, but thieves rob them all the time because they know that even in the best conditions, it is very difficult to identify them. A person cutting cable several hundred feet from the nearest camera in not concerned at all.
Companies have also hired security personnel or security companies to be on site during all non-working periods. The cost however can be more than five thousand dollars per month. Even with security personnel, often these construction or mine sites are very large and thefts can still occur. Patterns of guard duty or areas of difficult lighting or blocked visions are susceptible. There is still a human element that can cause failure even to the extent of an inside theft ring.
Security systems are typically employed in residential and urban commercial settings where it is important to prevent and detect intrusion. Some improvements have been made in the field. Examples of references related to the present invention are described below, and the supported teachings of each reference are incorporated by reference herein:
U.S. Pat. No. 5,973,604 by Eslambolchi, et al. discloses that lightning strikes on or proximate to an optical fiber cable may be detected via a lightning detector (18) that monitors the characteristics of voltage present on a metallic sheath (12) associated with the cable. The lightning detector (18) detects excessive voltage levels, spikes and/or frequency variations associated with a lightning strike and generates an alarm signal communicated to a central monitoring facility.
U.S. Pat. No. 6,934,426 by Rich, et al. discloses a fiber optic security sensor cable and system for using the cable. The cable includes a optical fiber encased in a first jacket, a power cable encased in a second jacket, and an overjacket encasing both the first jacket and the second jacket where the fiber is utilized to securely transmit data and provide a response to a sensed disturbance to the sensor cable. The system provides secure data transmission and power distribution via the sensor cable where one optical sensing fiber along the path of a data fiber responds to a sensed disturbance to the sensor cable. The system's sensor cable is enabled to detect disturbances at a processing unit where the sensor cable is either physically routed adjacent to the processing unit or within the processing unit. The system can further include more than one processing unit in the form of auxiliary units such as repeaters, power amplifiers, power outlets, data routers, and any similar electronic device. The system can also include a plurality of processing units which are arranged along the data path, wherein the sensor cable is physically routed within at least one of the processing units. The system's processing units may include at least one that is a microprocessor based signal processor.
U.S. Pat. No. 6,150,940 by Chapman, et al. discloses an anti-theft power cord for use with electrical devices has sensors for detecting removal of the cord from an electrical receptacle and for detecting the removal of the cord from the device sought to be protected. Control systems associated with each of the sensors activate alarms when receiving signals from the sensors. The control systems, comprising microcontrollers, also communicate with one another along the power cord and will sound an alarm if the cord is cut. A battery backup system is provided to allow the power cord to function as an anti-theft device even during a power failure without sounding false alarms.
U.S. Pat. No. 4,731,810 by Watkins discloses a backup security system for the telephone company lines of a protected home located in a neighborhood in which all the homes have a.c. supply lines connected to a common power transformer. The protected home, in addition to being provided with a conventional security system, is provided with a line-cut monitor, a PWM transmitter, and a conflict avoidance circuit. When the line-cut monitor senses that the telephone company lines for the protected home have been cut by an intruder, it provided a signal for gating an alarm signal from the conventional security system to the PWM transmitter which impresses the alarm signal as high frequency signals on the a.c. supply lines in the neighborhood. A neighboring home in the neighborhood is provided with a PWM receiver, telephone company lines and an automatic telephone communicator. The PWM receiver in the neighboring home responds to the high frequency signals on the a.c. supply lines and provides a digital signal to the automatic telephone communicator causing it to seize the telephone company lines for the neighboring home and send a message informing a central station that an intruder has broken into the protected home. The conflict avoidance circuit in the protected home enables the PWM transmitter therein to impress high frequency signals on the a.c. supply lines in the neighborhood only when there is an absence of any other high frequency signals on the a.c. supply lines in the neighborhood.
The inventions heretofore known suffer from a number of disadvantages which include being ineffective, being inefficient, being too expensive, being limited in application, being limited in adaptability, being burdensome to use, and being unreliable.
What is needed is a cable theft monitoring system that solves one or more of the problems described herein and/or one or more problems that may come to the attention of one skilled in the art upon becoming familiar with this specification.